2 Pack of Oasis PF PLUS - 10ml each Oasis TEARS PF PLUS Preservative-Free lubricant eye drops are packaged in an innovative ophthalmic multi-use bottle that prevents contamination through the use of a patented closing tip, valve and air venting system that prevents microbial entry into the bottle. This proprietary system keeps Oasis TEARS PF PLUS sterile for up to 90 days after opening. Lubricant eye drops, which are packaged in traditional multi-use bottles, contain preservatives to prevent microbial growth. Preservative-free lubricant eye drops are commonly packaged in unit-dose vials. These vials are small plastic one-time-use containers. The Oasis TEARS brand of eye drops deliver instant relief to dry eyes with its adherence and viscoadaptive qualities.